We're going to turn to more questions on that sex scandal involving general petraeus and his younger biographer, paula broadwell. Did she become obsessed and then snap when a rival emerged? Linsey... See More
We're going to turn to more questions on that sex scandal involving general petraeus and his younger biographer, paula broadwell. Did she become obsessed and then snap when a rival emerged? Linsey davis has that story. Reporter: To the outside eye, paula broadwell seemed to be living a picture-perfect life. The best-selling author shared this idyllic home with her radiologist husband and two sons. Prompting the question so many are now asking. Why was she willing to risk it all for an affair? The detail. He can turn water into bottled water. Reporter: While broadwell said this about the book's portrayal of the general. I'm not in love with david petraeus. Reporter: The two became close when she was interviewing him. him. Reporter: People around petraeus says she was gushy about him. That they shot she was in love with him. According to dr. Laura berman, the potential to lose judgment or have erratic behavior, is often the result of the passion of new love. The addiction center of your brain is firingas if you're addicted to a drug. Reporter: Around the time petraeus broke off the affair, jill kelly began to receive anonymous e-mails sent from broadwell's computer. So mails she found so threatening, she contacted authorities. In an affair, there's attachment. And there can be jealousy. Reporter: It's not the first time a very private infidelity has unraveled so publicly. In the case of john edwards, he wasn't as forthcoming, even as the affair was exposed, as he ran for president. The story's untrue. Ridiculous. Reporter: In 2007, nasa astronaut lisa now drove 1,000 miles to confront a woman who was having a relationship with her lover, allegedly wearing a diaper so she wouldn't have to stop. While broadwell didn't go quite as far, her behavior has garnered even more headlines. The therapist we spoke to gave us the percentage of couples who have infidelity within their marriage. That percentage, more than half. 60%. Surprised at that. Linsey, thanks very much.
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